Call notification SMS Lib Not Working

I am using SMSLib 3.5.2 library to send / receive sms. I don't get a message when I try to do this using callback methods. Moreover, even the incoming call notification function is never called. Any help would be much appreciated .....

gateway = new SerialModemGateway(MODEM_IDENTIFIER, SERIAL_PORT, BAUD_RATE, MODEM_MANUFACTURER,"");

gateway.setInbound(true);

gateway.setOutbound(true);

ICallNotificationI ic = new ICallNotificationI();
Service.getInstance().setCallNotification(ic);

Service.getInstance().addGateway(gateway);

Service.getInstance().startService();

      

        
        
        
      

    

and the implementation interface of the ICallNotification class is never called:

public class ICallNotificationI implements ICallNotification {

@Override 
public void process(AGateway gateway, String callerId) {

    System.out.print("Hello Buddy in the call");
    MLog.log(Level.INFO, ".ICallNotification.Process", "We rececived call"
            + " from this number "+callerId);

}